PHP cookie example

abstract

This article contains handful PHP function ae_put_cookie for easy cookie setting and "Cookie Notepad" example which allow visitor to store text in his own browser cookie.

compatible

PHP 4.1.0 or newer

Cookie is a parcel of text sent by a web-server to a web-browser and then sent back unchanged by the browser each time it accesses that server. (-- Wikipedia definition)

PHP has a function setcookie since version 3.0, but this function is too low-level for simple usage.

Function ae_put_cookie below, sets cookie for current domain (removing 'www' subdomain to ensure that cookie will be accessible to top-level domain):

<?php
function ae_put_cookie($name, $value, $days=0)
{
    $cookie_host = preg_replace('|^www\.(.*)$|', '.\\1', $_SERVER['HTTP_HOST']);

    if (substr(strval($days), 0, 1) == 'f')
        $exp = 2147483640;
    else if (substr(strval($days), 0, 1) == 'r')
    {
        $exp = 1; $value = '';
    }
    else if ($days != 0)
        $exp = time() + intval($days)*86400;
    else
        $exp = 0;

    setcookie($name, $value, $exp, '/', $cookie_host);
}
?>

This first and second argument is this function is name and value of cookie, passed directly to setcookie function. Third argument may have one of the following values:

argument not specified (or zero): the cookie will be set as session cookie, so it will expire when user closes web-browser
positive integer: number of days before cookie will expire. If today is 5th of September and third parameter equals to 10, cookie will expire at 15th of September.
any string beginning with 'f', like word 'forever' -- cookie will stay at user's browser forever (~ till 2038 year)
any string beginning with 'r', like word 'remove' -- cookie will be removed

Here is an example, 'Cookie Notepad' which allows to store entered text as a cookie and edit it later:

<?php
error_reporting(E_ALL); // high level of error reporting

// copy-paste function ae_put_cookie here from above 

if (strtolower($_SERVER['REQUEST_METHOD']) == 'post')
{
    if (isset($_POST['notepad']))
    {
        $days = isset($_POST['days'])?$_POST['days']:'';
        ae_put_cookie('notepad', $_POST['notepad'], $days);
        header("Location: http://{$_SERVER['HTTP_HOST']}{$_SERVER['PHP_SELF']}");
    }
}

?>
<html><head><title>CookieNotepad</title></head>
<body>
<?php
if (!isset($_COOKIE['notepad']))
    echo "<b>Cookie for notepad is not set</b><br>";
?>

<form action="<?=$_SERVER['PHP_SELF']?>" method="post">
Text:<br>
<textarea rows="10" cols="60" name="notepad">
<?php
if (isset($_COOKIE['notepad']))
{
    // escape HTML tags and entities
    $s = str_replace('&', '&amp;', $_COOKIE['notepad']);
    $s = str_replace('<', '&lt;', $s);
    $s = str_replace('>', '&gt;', $s);
    echo $s;
}
?></textarea>
<br>
Third argument for ae_put_cookie:<br>
<input type="text" name="days" size="10"><br>
(empty - session cookie, 'f' - forever, 'r' - remove, integer &gt; 0 - number of days in future)
<br><br>
<input type="submit" value="create/save">
</form>
</body>
</html>

tested by AnyExample.com on 2006-09-18

PHP 5.1.4 :: Microsoft Internet Explorer 6.0
PHP 4.4.2 :: Firefox 1.5

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